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|ID||Category||Severity||Type||Date Submitted||Last Update|
|0001041||[1003.1(2013)/Issue7+TC1] Shell and Utilities||Comment||Enhancement Request||2016-04-03 09:56||2017-08-03 16:30|
|Priority||normal||Resolution||Accepted As Marked|
|Section||XCU.4. cksum, compress, uncompress, zcat|
|Page Number||Too many pages|
|Line Number||Too many lines|
|Final Accepted Text||Make the changes specified in Note: 0003648 and Note: 0003813.|
|Summary||0001041: Encourage implementations to include better integrity checksum, compression and decompression utilities if possible.|
As we know, there are SHA-family of hash algorithms, and LZMA family of compression algorithms.
The SHA-family offers state-of-the-art security, while LZMA offers a significant improvement on compression ratio over DEFLATE, which in turn I believe offer better compression ratio over LZW algorithm of which compress(1), uncompress(1), and zcat(1) implements.
I think if Single Unix Specification is to mandate checksum and compression utilities, it might as well ask implementers provide a good one. Therefore I think we can discuss the possibility of bringing new apps in.
Add to rationale section of cksum(1) << EOF
Implementations are encouraged to provide utilities that implement hash and integrity checksum algorithms of higher security.
Add to rationale section of compress(1), uncompress(1) and zcat(1) << EOF
Implementations are encouraged to provide utilities that implement data compression algorithms of better compression ratios.
edited on: 2017-08-03 16:17
The following are proposed changes for cksum. The changes for compress etc. will be added as a separate note.
On page 2584 line 83831 section cksum, change:
The cksum utility is typically used to quickly compare a suspect file against a trusted version of the same, such as to ensure that files transmitted over noisy media arrive intact. However, this comparison cannot be considered cryptographically secure. The chances of a damaged file producing the same CRC as the original are small; deliberate deception is difficult, but probably not impossible.to:
The cksum utility is typically used to quickly compare a suspect file against a trusted version of the same, such as to ensure that files transmitted over noisy media arrive intact. However, this comparison cannot be considered cryptographically secure. This utility should be avoided whenever non-trivial requirements (including safety and security) have to be fulfilled.
On page 2585 line 83847 section cksum, insert a new first paragraph of RATIONALE:
The cksum utility is included in this standard for reasons of portability but is not suitable for uses where non-trivial requirements (including safety and security) have to be fulfilled. Implementations are encouraged to provide utilities that implement hash and integrity checksum algorithms of higher security and to keep up to date with developments in this area.
edited on: 2017-08-03 16:27
On Page xlvi (Informative References) add the following in proper alphabetical order:
IETF RFC 1951DEFLATE Compressed Data Format Specification version 1.3
On Page 2602 replace the entire page (lines 88476-84515) with the following:
NAMEcompress, uncompress, zcat - compress and decompress data
On page 2603, L84516-84517 replace the INPUT FILES section with:
INPUT FILESIf file operands are specified, the corresponding input files contain the data to be compressed or decompressed.
On page 2603 lines 84540-84549, replace the STDOUT, STDERR, and OUTPUT FILES sections with:
STDOUTFor the compress and uncompress utilities, standard output shall be used if no file operands are specified, if a file operand is '−', or if the -c option is specified. Otherwise, standard output shall not be used.
On page 2603 line 84553 (compress EXIT STATUS section), change:
The following exit values shall be returned
The following exit values shall be returned for compress
On page 2603 line 84558 (compress EXIT STATUS section), add:
The following exit values shall be returned for uncompress and zcat:
On page 2604 L84559-L84560 replace the CONSEQUENCES OF ERRORS section with:
CONSEQUENCES OF ERRORS
On page 2604 L84572-84574, replace the last paragraph of APPLICATION USAGE with:
In addition to trying file and file<tt>.Z</tt> when looking for a file to decompress, some implementations of uncompress and zcat also try suffixes for other known compression algorithms if neither file nor file<tt>.Z</tt> is found. This version of the standard allows, but does not require this behavior. Portable applications should always specify the full pathname (including the suffix) of files to be decompressed.
On page 2604 lines 84577-84583 replace the RATIONALE, FUTURE DIRECTIONS, and SEE ALSO sections with:
Replace the entire uncompress page (P3337-3339) with a pointer page to compress.
Replace the entire zcat page (P3471-3472) with a pointer page to compress.
|2016-04-03 09:56||dannyniu||New Issue|
|2016-04-03 09:56||dannyniu||Name||=> DannyNiu/NJF|
|2016-04-03 09:56||dannyniu||Section||=> XCU.4. cksum, compress, uncompress, zcat|
|2016-04-03 09:56||dannyniu||Page Number||=> Too many pages|
|2016-04-03 09:56||dannyniu||Line Number||=> Too many lines|
|2017-03-23 16:02||geoffclare||Note Added: 0003648|
|2017-04-06 15:07||agadmin||Interp Status||=> ---|
|2017-04-06 15:07||agadmin||Summary||Encourage implementations to include better integerty checksum, compression and decompression utilities if possible. => Encourage implementations to include better integrity checksum, compression and decompression utilities if possible.|
|2017-07-30 01:12||Antonio Diaz||Issue Monitored: Antonio Diaz|
|2017-08-03 16:17||geoffclare||Note Edited: 0003648|
|2017-08-03 16:18||rhansen||Note Added: 0003813|
|2017-08-03 16:21||rhansen||Note Edited: 0003813|
|2017-08-03 16:23||rhansen||Note Edited: 0003813|
|2017-08-03 16:23||rhansen||Note Edited: 0003813|
|2017-08-03 16:26||rhansen||Note Edited: 0003813|
|2017-08-03 16:27||rhansen||Note Edited: 0003813|
|2017-08-03 16:30||Don Cragun||Final Accepted Text||=> Make the changes specified in Note: 0003648 and Note: 0003813.|
|2017-08-03 16:30||Don Cragun||Status||New => Resolved|
|2017-08-03 16:30||Don Cragun||Resolution||Open => Accepted As Marked|
|2017-08-03 16:30||Don Cragun||Tag Attached: issue8|
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